ACCELERATED DRYING OF PLASTER CAST WITH A MICROWAVE OVEN
Charles Asbelle, Gerald Porter · 1972
Early medical microwave applications proceeded without modern EMF safety protocols, highlighting ongoing gaps in healthcare EMF protection.
Plain English Summary
This 1972 technical report by Charles Asbelle and Gerald Porter explored using microwave ovens to accelerate the drying process of plaster casts. The research developed prototype microwave technology specifically for medical applications, investigating how microwave energy could speed up what was traditionally a lengthy air-drying process.
Why This Matters
This early research represents a fascinating intersection of microwave technology and medical applications, predating widespread public awareness of EMF health concerns by decades. The study occurred during the initial commercialization of microwave ovens, when engineers were exploring diverse applications for this powerful electromagnetic technology beyond food heating. What makes this particularly relevant today is how it demonstrates the medical field's early adoption of high-power microwave devices without comprehensive safety protocols we now recognize as essential. The research likely involved exposing both patients and medical staff to significant microwave radiation during the drying process, at power levels potentially far exceeding what we'd consider safe for extended human exposure. This historical example illustrates how new EMF technologies were often implemented in medical settings before thorough biological safety assessments, a pattern we continue to see with emerging wireless medical devices today.
Finding
For the drying time of a 3 kg. knee cast to a level of mechanical workability can, for example, be reduced from the twelve hours required by a hot air oven to 30 minutes with an air-assisted microwave oven.
In their words
“For the drying time of a 3 kg. knee cast to a level of mechanical workability can, for example, be reduced from the twelve hours required by a hot air oven to 30 minutes with an air-assisted microwave oven.”
Figures from the Original Paper
Diagram extracted from the original research document.
Exposure Information
Specific exposure levels were not quantified in this study. Duration: 30 minutes for knee cast, 20 minutes total for initial tests
Study Details
To investigate the use of microwave energy for accelerating the drying of plaster casts and to establish design specifications for a prototype oven
Three approaches involving microwave equipment were tested including units from Sears-Roebuck, Litto...
Microwave drying reduced drying time from 12-24 hours to approximately 30 minutes for a 3 kg. knee c...
Microwave drying of 'set' orthopaedic plaster is a viable process. Drying time can be reduced from 12 hours to 30 minutes with an air-assisted microwave oven. Air assistance is beneficial for achieving high drying rates and good quality products. The process yields a product with a hemihydrate core and dihydrate exterior. No observable differences in strength, shrinkage, and mechanical capability were noted compared to conventionally dried samples.
Show BibTeX
@article{accelerated_drying_of_plaster_cast_with_a_microwave_oven_g5815,
author = {Charles Asbelle and Gerald Porter},
title = {ACCELERATED DRYING OF PLASTER CAST WITH A MICROWAVE OVEN},
year = {1972},
}